31 December 2018

It’s time for this blog’s longest running tradition! (Okay, the only tradition, if we’re honest.) It’s the eleventh annual look at trends in Marmorkrebs publishing!

As mentioned back in 2016, the graph above includes journal articles and book chapters. There were no book chapters this year, however. I feel compelled to add a second graph, plotting only the journal articles. The graph below is much more what this year felt like:

A barnstormer of a bumper crop of a year that was much busier than any before. But 2016 comes out on top because a single book dropped with a bunch of articles on Marmorkrebs. But several of those were reviews, and that they all came out in one volume meant it felt like one event instead of nine. Honestly, I think the activity in Marmorkrebs papers coming out in journals is a better indicator of the expansion of the field.

Announcing the sequencing of the Marmorkrebs genome, the first for a decapod crustacean.

Documenting the spread of Marmorkrebs in Madagascar since their detection about a decade earlier.

What was strange, though, was that almost none of the news coverage (of which there was a lot) focused on either of those two things. Most focused on the fact that cloning crayfish were a thing, which we have known from 2003. Some focused on the invasive nature of Marmorkrebs, but tended to talk about their spread in Europe rather than Madagascar. Having the first decapod crustacean genome, which might have been the biggest long term result from this paper, was very underplayed.

Another trend was researchers started to adopt the name Procambarus virginalis, after the name was proposed three years ago. The initial 2015 proposal was a “naked name” (nomen nuden in taxonomic lingo) with none of the typical descriptive work to accompany the new Linnean name, and the community generally used Procambarus fallax forma virginalis in 2016 and 2017. But having a proper taxonomic paper published in 2017 seems to have turned the tide, and P. virginalis seems to now be the accepted name in the community.

With the trendline continuing to head up, and two papers with 2019 cover dates already out, the state of Marmorkrebs research is strong.

Ecosystems increasingly face concurrent invasions by multiple species, but knowledge about relationships among invasive species is under studied. We examined agonistic encounters among signal crayfish Pacifastacus leniusculus, marbled crayfish Procambarus virginalis, and the common yabby Cherax destructor, none native to Europe, to assess the influence of aggression on their success in a sympatric environment. In interspecific interactions, similar-sized signal crayfish were significantly more likely to initiate aggressive encounters and won significantly more fights against similar-sized opponents. The marbled crayfish was the least aggressive and least successful in agonistic interactions. The mean number of fights, fight duration, and number and duration of low and high intensity fights varied significantly between intra- and inter-specific interactions, tending to be more pronounced in conspecific encounters. We concluded that crayfish species differ in fighting strategies employed during intra- and inter-specific interactions. Of the species evaluated, the signal crayfish shows the highest potential to establish dominance. However, factors such as growth rate, reproductive potential, ecosystem variables, and temperature of habitat may alter the competitiveness of an invader.

The educational publication contains microphotographs and description of histological preparations of the structure of marbled crayfish. The above materials may be used both for carrying out laboratory work on disciplines “Histology”, “Cytology”, “Cell Biology”, “Special Practice”, and for self-study of relevant educational topics. Designed for specialists in the field of hydrobiology and histology, students and graduate students of institutions of higher education who studying in the field of “091 Biology”, “207 Water bioresources and aquaculture” and “162 Biotechnology and bioengineering”. The publication contains the results of studies conducted by President’s of Ukraine grant for competitive projects Ф75/142 «The reproductive potential of invasive species of Dnieper region reservoirs and their impact on bioproductivity formation» (№ 0118U006319) of the State Fund for Fundamental Research.